Alarm and control device



July 3, 1928.

M. E. FULTZ ALARM AND CONTROL DEVICE w M IL U D 0 M Filed Dec. 8,- 1924 /nyenfaff M//es E /7//72 Patented July 3, 1928.

UNITED STATES PATENT OFFICE.

MILESE. FULTZ, OF BROOKLYN, NEW YORK, ASSIGNOR T0 WESTERN ELECTRIC OOI- PANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

ALARM AND CONTROL DEVICE.

Application ledDecember 8, 1924. Serial No. 754,640.

This invention relates to alarm and control devices used in fluid flow systems and it has special reference to devices which are adapted for use in connection with high power water-cooled vacuum tube systems.

An object of this invention is to provide a simplified and effective valve arrangement operative as a result of changes in rate of iiow rather than changes in pressure. A feature by which this is accomplished is the employment of a movable valve member restored to normal position by the force of gravity.

A further object of this invention is to render the alarm and control devices sensitive to a critical rate of flow through the valve. A feature tending to the fulfillment of this object is a valve structure in which a movable valve member is provided with lateral orifices or ports whereby a definite point of operation is secured.

A still further object of this invention is to prevent the fluid from engaging the electrical contact elements which control the devices to be operated as a result of abnor-y mal changes in the rate of ow. A feature whereby this is accomplished is a valve struct-ure having contact elements enclosed within a. hollow dome whereby the air entrapped therein serves as a water-tight seal.

This invention is especially applicable t0 high power vacuum tube systems ink which, on account of the excessive heat generated, it is ne'cessar'v to cool the anodes of the vacuum tubes by means of a cooling medium such as water. In such systems the vacuum tube anode is encased in a hollow water jacket into which cooling water is introduced by means of a pipe line and a coil of rubber hose. A similar coil and line serve `as an outlet for the jacket.

To prevent power from being applied to the anode when cooling water is not flowing through the iacket and to insure that power will be immediately cutoff when the rate offiow of cooling water falls below a predetermined value, it has been found advantageous to insert a flow alarm device in the water supply pipe line.

The present apparatus for accomplishing the above mentioned result comprises a water flow alarm device comprising a valve having a gravity restored valve member provided with lateral orifices or ports for rendering the member sensitive to a critical rate of flow of cooling water and having contact elements enclosed in a hollow watertight dome whereby the air entrapped therein serves as a pressure cushion for preventing the fluid from rising to the level of the contact elements. The contacts are thereby protected from corrosion and short circuit. These elements are associated with a circuit for controlling the application of space current to the vacuum tube system.

A more comprehensive understanding of the novel features of this invention can be obtained by reference to the drawings in which:

Fig. 1 is a plan vi'ew showing in detail thei mechanical structure of the invention; an

Fig. 2 is a circuit diagram showing the association of the device illustrated in Fig. 1 with a high power vacuum tube system.

Referring to Fig. 1 the valve casing 10 is that of a common type of valve having a valve member 11 in the form of a hollow cylinder with aflange 12 which extends beyond a periphery of the cylindrical portion 13. The outside lower surface of the flange 12 seats on the shoulder 14 surroundingthe valve seat. The cylindrical portion 13 is provided with lateral orifices or ports 15 through which flow is permitted when the valve opens. An insulating rod 16 rigidly fastened to the valve member 11 has mounted thereupon a metallic head or contact member 17. An insulating disc 19 is rigidly fastened to a hollow cylindrical plu 18 which is provided with threads adapted to engage corresponding threads of the valve casing 10. Extending through the metallic plug 18 are hollow insulating cylinders 20 which encase conductive rods 21. To the inner extremities of the rods 21 are connected spring contact strips 22 which are securely fastened to the insulating disc 19. The outer extremities of the rods 21 are threaded and provided with nuts 23 for circuit connections.

A hollow dome 24 is provided with threads adapted to engage corresponding threads of the plug 18 thereby producing an air-tight and a water-tight seal. The spring contact strips 22 are provided with contact points 25 which may be bridged by the metallic head 17. This head is rounded so that the resiliency of the spring contact strips 22 tends to force it down. The upward movement of the valve member 11 is limited by the engagement of a shoulder 26 of the insulating rod 16 withthe insulating disc 19. This arrangement prevents the contact points 25 from riding beyond the curved portion of the head 17.

Referring now to Fig. 2 a microphone 30 in series with a source of direct current or battery 31 supplies speech waves to the modulator k32 which may be of any well known type. High frequencywaves to be modulated b v the speech frequency waves are supplied by the source 33. The resultant modulated waves are applied to a high power water-cooled amplifier comprising either one or a number of tubes 34 in paral-V lel each having an internal cathode 35 and grid or control electrode 36 and external anode 37. High potential direct current is supplied to the anode 37 from the source 38 which has one terminal grounded. Amplified high frequency waves are supplied to the antenna 39 through the coupling coils 40. Blocking condenser 41 prevents direct current from the source 38 from reaching the antenna and high frequency -choke coil 42 limits the high frequency current impressed upon the direct current source 38. A, battery 56 serves as a' filament heatingl source. c y

The anode 37 of the tube Y34 is encased in the water jacket 43, cooling water being supplied by the source 44. Incoming water flows from the source 44, through the valves A and B and the water flow alarm device 45, through coil of hose 47 to the water Jacket 43. Outgoing water vflows through the hose coil 48 to outlet 49.

A circuit breaker or over-load release coil 50 having contacts 51 is inserted in the direct current plate supply line. Battery 52 and no -wOItage-release coil 53 are included in a control circuit 60. A predetermined rate of flow of cooling water through the water flow alarm device 45 causes the contact 54 made by points 25 and head 17 (Fig. 1) to close the control .'circ'uit 60 thereby closing the contacts 57. Insuicient flow of cooling water through the device 45 opens contact 54 operating the novoltage-release coil 53 to open the contacts 5l2 The manually restored overload release co1l 55 opens the contacts 51 when the direct current supply line is overloaded.

Operation.

In the operation of high power vacuum tube systems, it is necessary to utilize a water cooling system for the anodes of the tubes. To this end before power is applied to the tube 34 the water cooling system is put into operation. The valves A and B are both opened, then valve B is adjusted to permit the required flow for the total number of tubes used, in this case one tube. 'Ihe valve A is then gradually closed until the electrical circuit 60 is closed by the contact 54 of the flow alarm device 45. A decrease in flow through the main line will cause a corresponding change of flow through the device 45 thereby cansino' the contact 54 to open. Screening device (I is provided on the inlet side of device 45 to prevent particles of dirt from lodging on the walls of the valve and causing it to stick. v

Filament heating current from the battery 56 and plate current from the source 38 may then be applied to the tube 34. High frequency'A modulated waves from the modulator 32 are applied to the grid of tube 34 and the amplified high frequency waves are radiated from antenna 39.

Should the flow of water fall below a predetermined valuc, the force of gravity aided by the resilienc of Contact strips 22 causes the valve mem r 11 to drop.` Thereupon the contact 54 opens, allowing the no voltage release coil 53 to operate, opening the contacts 51 and -thereby preventing anode 37 of tube 34 from becoming overheated. Likewise overloading of the anode current supplied to tube 34 causes the overload release coil 55 to operate, breaking the contacts 51 and eliminating the danger of burning out the tube.

The number and disposition of ports or orifices 15 determine the displacement 0f the valve member 11 for any given rate of flow of cooling water. In a valve structure not provided with such ports the displacement changes rapidly, being large for low rates of flow but not changing appreciably with higher rates of flow. By providing ports this rapid changeI may be shifted and made to occur when the rate of flow flows below the desired amount. In this manner the head 17 does not bridge the contact points 25 until the ldesired rate of' flowVA is reached and any decrease in the rate of'flow causes a positive opening of the contacts thus made, thereby insuring a proper amount of cooling water through the iacket 43 at all times power is supplied to the tube 34.

lll

lll

By means of the air entrapped in hollow f dome 24 a water-tight seal is effected to prevent the water passing through the valve from reaching the contact points 25 ,and the conductive head4 17 enclosed in the dome. The possibility of corrosion of such contact members is thereby eliminated.

Because of the absence of friction between the valve member and other parts of the device, the member rides on water lowing through the device.4 Consequently the force of gravity is suicieiit to restore the member to normal position when water is not flowing.

It is understood that the present invention is not confined to the scope of the illustrated embodiment, but is to be limited only by the l sco e of the appended claims.

at is claimed is:

1. A cooling system for anodes of space discharge devices requiring a predetermined rate of flow of fluid in order to effectively cool the anodes in combination with a Huid flow device comprising a valve casing, a movable valve member provided with lateral orifices or ports, a conductive head sup rted by said movable valve member, a plura ity of contact points adapted to be bridged by said conductive head, and a hollow dome for enclosing said contact points.

2. In combination, a fluid supply line, a valve mechanism therefor, a switch ada ted to be actuated by said valve, and an air-tight 20 dome enclosing said switch and communicat- I valve casing,

ing with said suppl line, whereby said switch is protected rom the fluid 1n said 3. In a flow alarm device comprising a a movable valve member, a conductive head supported by said movable valve member, a pluralit of contact points adapted to be bridged y said conductive means, and an air-tight hollow dome for enclosing said contact points, a free passage from said valve casing to said hollow dome, the fluid passing through said device being prevented from reaching and engaging said contact members by the air in said air-tight hollow dome.

In witness whereof, II hereunto subscribe my name this 6th day of December A. D. 1924.

MILES E. FULTz. 

